using System.Text;
using System.Text.Json;

namespace Admin.NET.Plugin.AiDOP.Order;

/// <summary>
/// 销售订单保存前后快照与差异文本（用于操作日志）
/// </summary>
internal static class SeOrderAuditHelper
{
    private static readonly JsonSerializerOptions JsonOpt = new()
    {
        WriteIndented = false,
        Encoder = System.Text.Encodings.Web.JavaScriptEncoder.UnsafeRelaxedJsonEscaping
    };

    public static string SnapshotOrderJson(SeOrder o)
    {
        var dict = OrderToFlat(o);
        return JsonSerializer.Serialize(dict, JsonOpt);
    }

    public static string SnapshotEntriesJson(IEnumerable<SeOrderEntry> entries)
    {
        var list = entries
            .OrderBy(e => e.EntrySeq ?? 0)
            .Select(EntryToFlat)
            .ToList();
        return JsonSerializer.Serialize(list, JsonOpt);
    }

    public static string BuildCombinedSnapshotJson(SeOrder? order, List<SeOrderEntry> entries)
    {
        var root = new
        {
            header = order == null ? null : OrderToFlat(order),
            entries = entries.OrderBy(e => e.EntrySeq ?? 0).Select(EntryToFlat).ToList()
        };
        return JsonSerializer.Serialize(root, JsonOpt);
    }

    /// <summary>生成「变动前 / 变动后」可读文本 + 结构化 JSON</summary>
    public static (string Content, string? BeforeJson, string? AfterJson) BuildUpdateDiff(
        SeOrder beforeOrder,
        List<SeOrderEntry> beforeEntries,
        SeOrder afterOrder,
        List<SeOrderEntry> afterEntries)
    {
        var beforeCombined = BuildCombinedSnapshotJson(beforeOrder, beforeEntries);
        var afterCombined = BuildCombinedSnapshotJson(afterOrder, afterEntries);

        var sb = new StringBuilder();
        sb.Append("修改订单，订单编号：").Append(afterOrder.BillNo ?? "—").Append('。').AppendLine();

        var hBefore = OrderToFlat(beforeOrder);
        var hAfter = OrderToFlat(afterOrder);
        foreach (var key in hBefore.Keys.Union(hAfter.Keys))
        {
            hBefore.TryGetValue(key, out var ov);
            hAfter.TryGetValue(key, out var nv);
            if (string.Equals(ov, nv, StringComparison.Ordinal)) continue;
            sb.Append("  【").Append(key).Append("】变动前：「").Append(ov ?? "—").Append("」→ 变动后：「").Append(nv ?? "—").AppendLine("」");
        }

        var beforeById = beforeEntries.ToDictionary(e => e.Id);
        var afterById = afterEntries.ToDictionary(e => e.Id);

        foreach (var id in beforeById.Keys.Union(afterById.Keys))
        {
            beforeById.TryGetValue(id, out var eb);
            afterById.TryGetValue(id, out var ea);
            if (eb == null && ea != null)
            {
                sb.Append("  【新增明细】行").Append(ea.EntrySeq).Append(" 物料：").AppendLine(ea.ItemNumber ?? "—");
                continue;
            }
            if (eb != null && ea == null)
            {
                sb.Append("  【删除明细】行").Append(eb.EntrySeq).Append(" 物料：").AppendLine(eb.ItemNumber ?? "—");
                continue;
            }
            if (eb == null || ea == null) continue;

            var fb = EntryToFlat(eb);
            var fa = EntryToFlat(ea);
            var lineChanged = false;
            foreach (var key in fb.Keys.Union(fa.Keys))
            {
                fb.TryGetValue(key, out var ov);
                fa.TryGetValue(key, out var nv);
                if (string.Equals(ov, nv, StringComparison.Ordinal)) continue;
                if (!lineChanged)
                {
                    sb.Append("  【明细行").Append(ea.EntrySeq).Append("】物料 ").Append(ea.ItemNumber ?? "—").AppendLine();
                    lineChanged = true;
                }
                sb.Append("    ").Append(key).Append("：变动前「").Append(ov ?? "—").Append("」→ 变动后「").Append(nv ?? "—").AppendLine("」");
            }
        }

        var content = sb.ToString().TrimEnd();
        if (content.IndexOf('→') < 0 && content.IndexOf("【新增明细】", StringComparison.Ordinal) < 0 && content.IndexOf("【删除明细】", StringComparison.Ordinal) < 0)
            content = "修改订单，订单编号：" + (afterOrder.BillNo ?? "—") + "。（主表与明细字段无变化）";

        return (content, beforeCombined, afterCombined);
    }

    private static Dictionary<string, string?> OrderToFlat(SeOrder o) => new()
    {
        ["订单编号"] = o.BillNo,
        ["订单类型"] = o.OrderType switch { 1 => "销售", 2 => "计划", _ => o.OrderType?.ToString() },
        ["客户编码"] = o.CustomNo,
        ["客户名称"] = o.CustomName,
        ["签订日期"] = o.Date?.ToString("yyyy-MM-dd"),
        ["客户级别"] = o.CustomLevel?.ToString(),
        ["加急"] = o.Urgent == 1 ? "加急" : "普通",
        ["客户订单号"] = o.BillFrom,
        ["国家"] = o.Country,
        ["客户下单日期"] = o.RDate?.ToString("yyyy-MM-dd"),
        ["流程状态"] = o.FlowState,
    };

    private static Dictionary<string, string?> EntryToFlat(SeOrderEntry e) => new()
    {
        ["明细Id"] = e.Id.ToString(),
        ["行号"] = e.EntrySeq?.ToString(),
        ["物料编码"] = e.ItemNumber,
        ["物料名称"] = e.ItemName,
        ["规格"] = e.Specification,
        ["单位"] = e.Unit,
        ["数量"] = e.Qty?.ToString("0.######"),
        ["客户要求交期"] = e.PlanDate?.ToString("yyyy-MM-dd"),
        ["最终交货日期"] = e.Date?.ToString("yyyy-MM-dd"),
        ["系统建议交期"] = e.SysCapacityDate?.ToString("yyyy-MM-dd"),
        ["备注"] = e.Remark,
        ["进度"] = e.Progress switch { 0 => "再评审", 1 => "新建", 2 => "评审", 3 => "确认", _ => e.Progress?.ToString() },
        ["交付数量"] = e.DeliverCount?.ToString("0.######"),
    };
}